If the degree of a monomial is the sum of the exponents of its variables, so that x^3*y^2 is degree 5, what happens in the case of x^3*y^(-2)? Is it degree 1 or would you apply absolute value and also call it degree 5?

What did Euler wrongly assume when he first derived pi^2/6 from the infinite sum of 1/n^2? Doctor Jordan reveals two missteps initially committed by the famous mathematician on this now-classic result.

A student knows how to evaluate expressions and solve equations, but doesn't see the
difference between the two. Doctor Ian explains the distinction by way of an analogy to
phrases and sentences, illustrating throughout with examples, before leaving the
student with a mathematical statement for her to ponder further whether "an equation
is an expression with an equals sign."